Technical Field
In its most general aspect, the present invention refers to the food product packaging sector.
In particular, the present invention regards a packaging for food products comprising a container made of a flexible material, such as a pouch, bag and the like, and a related packaging method in particular not exclusively in sterile conditions.
The present invention also regards a flexible container for a package of the aforesaid type as well as a method for the production of said container.
Description of the Related Art
The use of packages composed of or comprising flexible material containers is well known, in particular, pouches, bags and the like for packaging liquid or semi-liquid food products such as for example drinks or juices, as well as solid food products having appropriate fluidity (or flow) characteristics, such as for example powder or granular food products.
Such containers are generally obtained from a sheet (or even several sheets) of an appropriate flexible material, which is folded and sealed at least on its side, so to define a bottom, two opposite side walls between which an inner space is formed for the food product, said opposite walls terminating on their upper part with a mouth for inserting the food product.
The packaging normally provides for the filling of the flexible containers with the pre-selected food product from the upper mouth and the subsequent sealing of the edges of the mouth, so to hermetically close the container with the food product inside and thus obtain the final package. The sealing operation can be carried out by directly heat welding or by ultrasound welding the aforesaid edges to each other so to make them integral by means of melting or, more frequently, by first interposing an opening and closing device provided with appropriate sealing surfaces between the edges of the open container and then heat or ultrasound welding the edges against the sealing surfaces of the opening and closing device. In the latter case, there is in fact the advantage of rendering the container reclosable after, for example, a partial administration of the food product contained therein.
More in particular, the aforesaid opening and closing device comprises a pourer body in a rigid plastic material for administering the food product, said pourer body being provided with said surfaces for the sealing between the opposite edges of the mouth, and an opening and closing element, normally a cap, associated in a removable manner with the pourer body, for example by means of a thread coupling for the unscrewing and screwing of the cap from and on the pourer body as necessary.
Although the package and packaging system described above substantially meet the object for which they were designed, they have several drawbacks which still today have yet to be resolved in a satisfactory manner.
One drawback lies in the fact that it is very difficult to optimally seal (i.e., without defects) the opening and closing device between the edges of the mouth of the open flexible container, in particular in substantially triangular cross-section zones near the pourer body in which the walls of the edges subjected to sealing diverge—this notwithstanding the generally good compatibility of the material subjected to sealing constituting the container and pourer body.
Consequently, it often occurs that the flexible container is not hermetically closed as desired, to the point that it can allow the exit of the food product contained therein towards the outside, as well as the entrance of air inside the container with consequent possible deterioration of the organoleptic characteristics of said food product and compromising the shelf-life indicated on the label.
Such drawback has greater importance where the flexible container was previously sterilized and the food product was packaged in sterile (or aseptic) conditions, for example due to its high degradability and/or for increasing its shelf-life.
Another drawback lies in the fact that the opening and closing device applied to the top of the flexible container can cause holes and/or tears in the walls of the container itself during the use of the package, due to its rigid characteristics which contrast with the flexible characteristics of the container. This can occur particularly in the case of clumsy use of the packaging but even during normal opening and closing operations of the container by means of the aforesaid device.
A further drawback lies in the fact that the packaging process with a flexible container of the aforesaid type is long and complex. In particular, in case of sterile or aseptic packaging, it is necessary to carry out in sterile or aseptic conditions not only the filling of the flexible container (upon being rendered it sterile) with the preselected food product, but also and above all the sealing operation to prevent the food product from being contaminated by bacteria or other impurities since the opening and closing device is applied to the flexible container while it is still open.
This implies that even the opening and closing device must be subjected to previous sterilization and that suitable sterility conditions must be maintained in at least until the completion of the sealing of the aforesaid device between the edges of the mouth of the container.
It is clear that all of the above renders the making and functioning of the equipment set for the above-described packaging considerably complicated and costly.
The application WO 98/23498 on behalf of The Coca-Cola Company describes a pouch for packing drinks. The pouch comprises two laterally sealed opposite walls and two gusset elements respectively arranged above and below the opposite walls so to define with the latter a space for containing a drink.
In particular, the upper gusset element is composed of a folded sheet made of a flexible and frangible material whose fold returns inward so to define a pocket at the upper end of the pouch for the insertion of a straw by a consumer, with which such consumer perforates said upper gusset element, so accessing the pouch content. In such a manner, a facilitated insertion of the straw inside the pouch is allowed, at the same time minimizing the risk of accidentally perforating or tearing the walls of the pouch, with consequent product outflow.
Nevertheless, it should be noted that the manufacture of the aforesaid pouch is rather complicated, since two separate sheets of flexible material are required for the aforesaid opposite walls; moreover, the sealing of separate gusset elements to the respective upper and lower edges of said walls is also required. The flexible material of the sheets must moreover have a limited resistance, so to be easily pierced by means of the aforesaid straw.
In addition, the application WO 98/23498 does not envisage the possibility of being able to reclose the pouch, once open, but limits its use in association with a straw or similar perforating means of the gusset element. Moreover, such use can be difficult for the consumer, since, in accordance with the application WO 98/23498, it is first necessary to “open” the pocket by folding outwardly one or both sheets of flexible material composing the walls of the pouch at an upper end position thereof, and then inserting the straw in the pocket until the gusset element is broken, so to access the contents of the pouch.
The problem underlying the present invention is therefore that of providing a package comprising a flexible container for packaging food products, in particular but not exclusively in sterile or aseptic conditions, as well as a relative packaging method which overcomes the drawbacks mentioned above with reference to the prior art.